Reproductive failure is a serious problem that has been addressed clinically by various assisted reproductive technologies, including in vitro fertilization (IVF) and embryo transfer (ET). These procedures might be expected to yield exceptionally high conception rates as in vitro fertilization provides embryos that appear normal at a morphological level for transfer into a fully primed recipient. Despite these efforts the success rate of IVF/ET is less than ideal. In the published data for IVF/ET in the United States and Canada in 1994, there were 26,961 initiated cycles of standard IVF. Of these, 86.2% led to retrieval and of these 90.2% led to a transfer. However, the overall success rate in terms of clinical pregnancies was 22.7% per initiated cycle and a 29.1% pregnancy rate per transfer.
Additionally, there appears to be a high incidence of early pregnancy loss after in vitro fertilization with a biochemical pregnancy rate of 18% and a spontaneous abortion rate of 27%. Thus, it appears that the IVF technique has been well optimized but implantation failure may be the cause for a large number of losses with ET and this peri-implantational loss is an area of potential improvement. A major factor in the success rate of various assisted reproductive technologies is endometrial receptivity, a transient state that must be coordinated with embryo development to implantation-competent blastocysts.
IVF is an expensive procedure and can be psychologically traumatic for a patient. Surgical procedures are required to collect eggs from a female for IVF and, following fertilization, further surgery is required to implant the fertilized eggs in the womb. The recipient must then wait for a period of time before it can be determined whether or not pregnancy has been established. In some cases, pregnancy may never be achieved despite repeated attempts, and these cases can represent a considerable expense to the patient and society, both in financial and human terms.
Therefore, until success rates of IVF can be improved, it would be desirable to be able to identify recipients for whom IVF is unlikely to be successful prior to treatment, so that such patients may avoid the above mentioned costs and trauma of the IVF procedure.
The present invention addresses these needs.